Extreme pressure platen-and-roller die-press for precise working of web structures

ABSTRACT

A die-press for precise high pressure deformation of web structures, including in typical embodiment a downward facing die platen having a die integral with the face, a guide platen fixed in plane-parallel spacing below the die platen; twin horizontal rollers of combined diameters greater than the plane-parallel spacing, and stacked in contact in parallel nearly over-and-under relation in the space between the platens; a reciprocable carriage rotatively mounting the ends of the rollers and having an extension adapted to travel along a guide during the working stroke to define the angle of the over and under relation of the rollers and thus the roller pressure, and apparatus to position a web between the upper roller and the die; a recess at the end of the guide platen relieves pressure as the working stroke is being completed and separates the roller from the work, and means for changing the over-and-under relation of the rollers maintains the roller and work separation on the return stroke.

tates atet May 1, 1973 EXTREME PRESSURE PLATEN-AND- ROLLER DIE-PRESS FOR PRECISE WURKING OF WEB STRUCTURES [76] Inventor: Remsen V. Wood, Riderwood, Md.

[22] Filed: May 28, 1971 [21] Appl. No.: 148,028

[52] US. Cl ..-..10l/269, 101/22 [51] llnt. Cl. ..B411l 3/16, B4lf 3/22 [58] Field of Search.., ..l01/22, 23, 24, 32,

[56] References Cited UNITED STATES PATENTS 1,924,288 8/1933 Reardon ..l01/269 2,913,931 11/1959 Hermann... ....l0l/269 3,299,803 1/1967 Taylor l l ..l01/5 3,236,177 2/1966 Perry et a1 ....l0l/269 3,323,454 6/1967 McFarland..... .,..l0l/269 3,370,533 2/1968 Hestra et al. 101/269 3,540,374 11/1970 Hudson 101/269 3,565,007 2/1971 Tyburski et al ..l01/269 ,Asso

Primary Examiner-Robert E. Pulfrey Assistant Examiner-E. M. Coven Att0rney.lohn F. McClellan, Sr.

A die-press for precise high pressure deformation of web structures, including in typical embodiment a downward facing die platen having a die integral with the face, a guide platen fixed in plane-parallel spacing below the die platen; twin horizontal rollers of combined diameters greater than the plane-parallel spacing, and stacked in contact in parallel nearly over-andunder relation in the space between the platens; a reciprocable carriage rotatively mounting the ends of the rollers and having an extension adapted to travel along a guide during the working stroke to define the angle of the over and under relation of the rollers and thus the roller pressure, and apparatus to position a web between the upper roller and the die; a recess at the end of the guide platen relieves pressure as the working stroke is being completed and separates the roller from the work, and means for changing the over-and-under relation of the rollers maintains the roller and work separation on the return stroke.

ABSTRACT I 1 Claims, 7 Drawing Figures Patented May 1, 1973 2 Sheets-Sheet l PEG. 2

FIGA

REMSEN V. WOOD INVENTOR ATTORNEY Patented May 1, 1973 3,730,088

2 Sheets-Sheet 2 FIG.6

0| 2 O GBOJ 4U K672 638 FIG.7

CONSTANT PRESSURE NALANCING SYSTEM l6 V 776 778 f DIFFERENTIAL PRESSURE DRIVE SYSTEM REMSEN V. WOOD INVENTOR EXTREME PRESSURE PLATEN-AND-ROLLER DlE-PRESSFOR PRECISE WORKING F WEB STRUCTURES The invention relates generally to web-working devices and particularly to high pressure die-presses and/or presses involving large areas such as engraving presses or steel rule die presses.

A principal object of the invention is to provide simple, high capacity apparatus for the production of very precisely dimensioned and detailed web structures, such as special films and foils, by one-pass high-pressure rolling of web stock. Examples of such special webs are diffraction grating replicas impressed in thin aluminized plastic films or in aluminum foil. Because any substantial reduction in quality between the die and the replicas produced from it in the web material is commercially intolerable, high fidelity is essential. And yet, since the spacing between adjacent ruled grooves in the die is exact to a few millionths of an inch, the angle of the grooves is precise to a fraction of a degree, and the depth of grooves is only fifty millionths of an inch, fidelity is very difficult to achieve, especially over any appreciable area.

To insure strength in the replica without waste and undue expense, web thicknesses in the range of onehalf-thousandth to about four-thousandths are used, depending on the material. Local thickness variations in available web materials amount to many times the groove depth of fifty-millionths of an inch. Consequently, very-high pressures must be exerted on the die to prevent unsightly bald spots in the product.

With some materials, controlled heating of the die or the web is employed to aid the rolling process. However, regardless of the exact technique used, uniformity of pressure on the web is the primary requirement, even though uniformity of pressure over wide areas of web is difficult to produce.

To avoid the need for extremely high instantaneous pressures, simple roller presses are indicated, but the near line-contact between rollers makes web adjustment at the contact unreliable. Additionally wraparound die mountings for such presses require substantial extra investment in each die installation.

The best compromise between pressure, performance, convenience, and economy is found in the roller-platen press. In this press the instantaneous pressure required is relatively low as compared with flat presses, although pressure at the line contact between roller andplaten is high. Using a short roller with heavy bearings at each end to apply the pressure to a die affixed to the platen, this type press is quite satisfactory for small area work.

Unfortunately, if a wider web must be processed, making a substantially longer roller necessary, several troubles appear in the conventional roller-platen press.

Anti-friction bearings which serve well under conditions of continuous rotation and heavy loads tend to fail when subjected to oscillatory loads of the same order. Larger diameter rollers, which would preserve bending tolerances in long-roller embodiments would also have larger tangential contact areas with the platen, requiring higher overall pressures to maintain unit area pressures.

Applying the necessary force to the bearings in a uniform manner over the length of the stroke to produce the high, uniform roller pressure needed requires extra mechanisms, with consequent limitations in accessibility and reliability, and with extra expense.

Other mechanical problems encountered using ordinary presses are: imprecise tracking, leading to wrinkling and other distortions of the web being worked; unsatisfactory pressure release, leading to sticking between roller and web; low retraction clearances on release, causing difficulties in threading and inspection of the work; upward facing dies, causing blemishes through accumulations of foreign material; and difficult, unreliable adjustment provisions.

In fulfillment of its objectives, the present invention solves these problems and provides a means of applying very high, reliably uniform roller pressure to wide area dies mounted on platens, with minimum difficulty and expense of construction and operation.

The invention is characterized by provision of intercontacting, coupled, rollers adapted for rolling between and exerting rolling wedging pressure between plane parallel platens, one of which has a die on the pressure face.

The above advantages and objects of this invention will become better understood on examination of the following description, and the drawings in which like parts are indicated by like reference numerals.

FIG. 1 is a perspective diagram illustrating the relations of the elements of the press of this invention;

FIGS. 2, 3 and 4 are side elevations of the FIG. 1 diagram illustrating three positions of operation of the FIG. ll elements;

FIG. 5 is an end elevation diagramming further adjustment capability of the invention;

FIG. 6 is a diagram of an actual embodiment of the invention, showing provisions for web handling and press operation, and FIG. 7 is a side elevation diagram of an embodiment of the invention. FIG. 1: die-platen or work platen 12 having a die 14 welded or otherwise affixed to the lower face is rigidly mounted in the machine by means not shown in the diagram. The web or work 16 is stretched tautly across the down facing die between feedroll l8 and take-up roll 20. The rolls are arranged for advancement of the worked portion of the web between each reciprocation of the press roller assembly 22 in contact with the web.

The press rollers 24 and 26 are mounted in over-andunder contact throughout the lengths of the rollers by sideplates 28, 30 in which the trunnions 32, 34 of the respective rollers are loosely mounted at each end of the rollers, preferably in anti-friction bearings.

The roller assembly 22 is supported by a guide platen 38 which is fixed in plane parallel spacing with work platen 12 above by means not shown.

In operation, the roller assembly 22 reciprocates between the guide platen 38 and platen-mounted die 14 above it, applying force to each in a direction tending to separate the two, thus pressing the web 16 against the die.

The amount of pressure applied is made a function of roller angle by the following provision. The diameters of the rollers are identical, and the two diameters taken together exceed the spacing dimension between the two platens, die-platen 12, 14, and guide platen 38. Due compensation can be made for work-thickness, if appreciable, but this is not a factor in web-work. As a result, the rollers wedge tightly between the platens when the plane through the roller axes approaches the vertical. 7 i

The wedging angle or pressure-angle of the roller couple between the platens is closely controlled according to precepts of this invention by guide bars 40, 42. By frame-means not shown in the diagram, the guide bars are fixed roughly parallel with the planes of the platens and offset from them. The tops of the guide bars are adapted to guide, during reciprocation, longitudinally extended ends 44, 46 of the side plates, which preferably have anti-friction followers 48, 50 for the purpose, during the workingor pressure-stroke of the reciprocating assembly 22. Positioning the followers in contact with the guide bars applies counterclockwise torque to the roller assembly 22 as viewed in FIG. 1, tending to wedge the rollers between the platens and this wedging pressure continues throughout the working stroke.

It was noted above that the roller trunnions are loosely mounted in the sideplates. This is one of the salient features of the invention. It makes the rollers, in effect, their own bearings, by imposing the defining pressures along the lengths of the rollers at the contacts between the plane-parallel surface above and below the roller couple and at the contact between the rollers themselves.

In the FIG. I view, the working stroke of the reciprocating carriage is from left to right, the rollers being pushed" by the side-plates. At the end of the working stroke, another feature of the invention comes into play, relief of the roller pressure while the rollers are still turning. This feature has been found to prevent sticking between roller and web on relief of roller pressure, to a reliability not otherwise achievable, and completely automatically.

The end 52 of the guide platen 38 which is away from the guide bars and which is thus reached by the rollers at the end of the working stroke, is downwardly (outwardly) contoured or relieved on the top surface. The relief is preferably in the form of a full-width longitudinal incline smoothly faired downward from the other part of the surface.

As the bottom roller descends this incline at the end of the stroke, pressure is gradually relieved, and the top roller cleanly separates from the web being pressed at a precisely determined point, aiding matching with the next-advanced portion of the web.

The return stroke is a clearance stroke, during which the web is advanced, so that a fresh web-surface is presented for pressing. Since the rollers are already separated from the work at this point, it is merely necessary to introduce additional clearance to allow return of the roller assembly free of the work.

Lifting the followers 48, 50 from the guide bars clears the roller assembly during the return stroke. The amount of clearance is determined by the degree of lift, and this feature provides extra clearance when needed for threading access or inspection.

FIG. 1 shows a further important provision of the invention, the roller assembly centering feature. It has been observed that the roller assembly carriage should be free of lateral constraint during the working stroke to avoid wrinkling and other uneven pressing of the web. Freedom is provided. As noted in the drawings, no

. lateral guidance is applied during the working stroke.

Instead, the carriage is recentered at the end of each return stroke through contact between vertical-axis rollers 58, 60, fixed with respect to the guide platen 38, on

either side, and centering wedges 54, 56, mounted to reciprocate with the roller carriage.

FIGS. 2, 3 and 4 diagram thepositions of the roller assembly during the working and return strokes.

In FIG. 2, the working stroke begins. Followers 48 and 50 have been brought down in the direction of the arc-ed arrow into respective contact with guide bars and 42, forcing web 16 against die l4 by wedging the rollers between the platens. The roller assembly 22 is now advanced at a constant rate from left to right in the Figure, pressing the work, until it reaches the end of the working stroke.

FIG. 3 shows the roller assembly at the end of the working stroke, descending incline 52, relieving pressure on web 16 during rolling contact with the web.

FIG. 4 shows upward tilt of the side frames 28, 30 of the roller assembly 22 indicated by the arc-ed arrow, prior to commencement of the return stroke, indicated by the straight arrow.

It will be noted that the die 14 is not shown in FIG. 4 as such. The press design of this invention does not require a separate die for all operations, since either or both platen members can be used directly for rolling web material to' thinner dimensions. So used, the platens themselves are dies.

From the foregoing structural and operating descriptions, many advantages of the present invention can be seen. Uniform pressure along the length of the top roller where it contacts the die is assured by the simple, certain relation of the elements.

The bottom or guide platen supports the bottom roller throughout the span of the roller. The bottom roller, in turn, because of the near-perpendicular relation of 'the roller axes with respect to the spaced platens, supports the span of the top roller; Thus bearing loads between the side plates and roller trunnions are relatively low, and, as noted, loose tolerances are allowable and desirable there.

Because the rollers are, in effect, their own bearings, uniform, high local pressures throughout the length of relatively small-diameter rollerswith consequently low tangential-area die contact can thus be imposed, even though the span of the rollers is great as compared with conventional presses.

FIG. 5 shows a frame-to-platen wedging adjustment. If the frame of the press were perfectly formed and rigid, the rollers were perfectly cylindrical, the platens were perfectly flat, and if the die and the web were both of perfectly uniform thickness, the FIG. 5 adjustment would be of little moment. As a practical matter, the adjustment co-acts significantly with several other inventive provisions. The Figure is an end view detail of the roller-platen elements assembled within encompassing frame 62, which aligns and secures the parts in operating relation. The frame 62 has inner surfaces 64, 66, at the top and the bottom which are generally parallel with and substantially co-extensive in length and breadth with platens l2 and 38 respectively.

Between the frame and the less rigid but more accurately fashioned platens, shims 68 are wedged and are fixed in position by screws or the like. These shims are adjusted to insure that the platens have the required surface figures to maintain uniform pressure from endto-end of the rollers throughout the entire working stroke.

It will be appreciated also that the guide bars 40, 42 (not shown) are likewise individually alignable with respect to the fixed portion of the press as represented by the frame, to provide the tracking necessary for the followers 48, 50 (shown in the Figures) to position the trunnions properly at every portion of the working stroke.

The embodiments of FIGS. 1-5, even in large sizes, are well adapted for manual operation because of the enormous mechanical advantage provided, coupled with the unique bearing arrangement, which is relatively frictionless as compared with conventional arrangements necessary to do the same job.

Advancement of the web material by hand presents no particular problem either, although some degree of braking friction is desirable in both spindles to hold the work 16 taut against the die 14 during stroke-turnaround.

However, the design is amenable to partial or complete drive-mechanization without sacrifice of ac cess, reliability, precision, or simplicity.

FIG. 6 diagrams in side elevation an embodiment of the invention in which relative roller position, and hence roller pressure and clearance on the working and return strokes respectively, is automatically set under power by mechanical means.

In FIG. 6, the rollers 624, 626 are disposed between the platens 612, 638, and reciprocate as described earlier. However, the side plates, represented by 628 shown, are contoured to guide on one or more fixed horizontal-spindle rollers 640. The side plates reciprocate in-plane and do not lift free of the guides as they did in the prior embodiment. Only one roller, 626 (this may be either roller) is journalled directly in the side plates. The other. roller is movably attached to the side plates, as by linkage 670, 672. The linkage is driven relative to the side plates by a power unit 674 which rides with the linkage on the side plate and supplies the necessary relative motion between the rollers.

A synchronized power-reciprocator shaft as indicated at 680, is attached to side plate 626.

FIG. 7 diagrams a third embodiment of the invention in which the rollers 724, 726 are respectively journalled in the forked ends of piston rods 728, 770, ex tended to the rollers by drive pistons 776,778. The drive pistons are preferably actuated through a pressure balancing, interconnected fluid pressure system as indicated.

In all the embodiments, stroke turnaround and other cyclic events are easily set by appropriately located limit switches, limit valves, or similar means, according to conventional methods, and supporting framework is supplied according to known practice.

Synchronized advancement of the web can be achieved by any of numerous means. For example, in FIG. 1 the arms 44, 46 are adapted to contact the flanges of take-up spool and to rotate the spool on the return stroke of the carriage.

Obviously many modifications and variations of the present invention are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed and desired to be secured by U. S. Letters Patent is: g

l. A roller-platen material press wherein said press is adapted to receive material to be pressed between a roller means and a cooperating planar means for pressing, comprising: first and second means for pressing, said first and second means for pressing being substantially planar; means for fixing the first and second means for pressing in parallel-spaced facing relation, first and second roller means, the dimension of the combined diameters of the roller means being so proportioned as to exceed the dimension comprised by said parallel spacing between the first and second means for pressing less the thickness of material which the press is adapted to receive, means for movably aligning the first and second roller means in substantially continuous contact with each other in a plane approaching perpendicularity to the first and second means for pressing, with the first roller means in substantially continuous contact with the first means for pressing and the second roller means in substantially continuous contact with the second means for pressing, including means for releasibly wedging the first and second roller means between the first and second means for pressing by forcing the roller means against each other in a direction substantially parallel with the first and second means for pressing, means for reciprocating the roller means in a first rolling direction thereof with the releasible wedging means forcing the roller means together, thereby comprising a pressure stroke, means for reciprocating the roller means in a rolling direction opposite the first rolling direction with the wedging means released, thereby comprising a return stroke, and means for permitting said substantially continuous contact of the roller means to define the direction of said rolling during a portion of said pressure stroke.

2. A roller-platen material-press as recited in claim 1, wherein the means for pressing includes a die disposed on one of said means for pressing in a position for exertion of rolling pressure thereon by a said roller means.

3. A roller-platen material-press as recited in claim 2, wherein said first and second roller means are of equal diameter.

4. A roller-platen material-press as recited in claim 3, wherein one of said means for pressing has a relieved area at a position adapted to lessen pressure on the roller means proximate one end of the means for pressing.

5. A roller-platen material-press as recited in claim 4, wherein the releasible wedging means includes a sideplate assembly, wherein the sideplate assembly rotatably mounts the first and second roller means and has clearance for pivoting about one of said rotatably mounted roller means and wedging the roller means between the means for pressing, wherein the sideplate assembly has an extended portion, wherein at least one guide is provided, and wherein said at least one guide is positioned for engaging the extended portion of the sideplate assembly and limiting pivoting in said wedging pivotal direction thereof.

6. A roller-platen materiaLpress as recited in claim 5, wherein said at least one guide limits only the side plate assembly extended portion pivoting during the pressure stroke, and wherein the rolling contacts of the roller means on passage between the means for pressing define the other motions of the roller means relative to the means for pressing during the working stroke.

7. A roller-platen material-press as recited in claim 5, and laterally constraining means positioned for laterally aligning the roller means with respect to the means for pressing at a time when the sideplate assembly extended portion is pivoted away from engagement with said at least one guide.

8. A roller-platen material-press as recited in claim 3, wherein the sideplate assembly includes first and second portions respectively mounting said first and second roller means, and a connector movably engaging the first portion of the sideplate means relative to the second portion of the sideplate means for thereby accomplishing said wedging of the roller means between the means for pressing.

9. A roller-platen material-press as recited in claim 3, wherein the releasible wedging means and the means for reciprocating comprise first and second separately reciprocable means respectively mounting the first and second roller means.

10. A roller-platen material-press as recited in claim 5, wherein said rotatable mounting by the sideplate assembly is substantially loose relative to the tightness of said wedging of the roller means between the means for pressing, thereby comprising said permitting means.

1 1. A roller-platen material-press as recited in claim 1, and additionally a frame exteriorly proximate and substantially co-extensive with the width of a said means for pressing, and means for applying force selective between the means for pressing and the frame and thereby adjusting roller contact pressures with said means for pressing by altering the surface configuration of said means for pressing. 

1. A roller-platen material press wherein said press is adapted to receive material to be pressed between a roller means and a cooperating planar means for pressing, comprising: first and second means for pressing, said first and second means for pressing being substantially planar; means for fixing the first and second means for pressing in parallel-spaced facing relation, first and second roller means, the dimension of the combined diameters of the roller means being so proportioned as to exceed the dimension comprised by said parallel spacing between the first and second means for pressing less the thickness of material which the press is adapted to receive, means for movably aligning the first and second roller means in substantially continuous contact with each other in a plane approaching perpendicularity to the first and second means for pressing, with the first roller means in substantially continuous contact with the first means for pressing and the second roller means in substantially continuous contact with the second means for pressing, including means for releasibly wedging the first and second roller means between the first and second means for pressing by forcing the roller means against each other in a direction substantially parallel with the first and second means for pressing, means for reciprocating the roller means in a first rolling direction thereof with the releasible wedging means forcing the roller means together, thereby comprising a pressure stroke, means for reciprocating the roller means in a rolling direction opposite the first rolling direction with the wedging means released, thereby cOmprising a return stroke, and means for permitting said substantially continuous contact of the roller means to define the direction of said rolling during a portion of said pressure stroke.
 2. A roller-platen material-press as recited in claim 1, wherein the means for pressing includes a die disposed on one of said means for pressing in a position for exertion of rolling pressure thereon by a said roller means.
 3. A roller-platen material-press as recited in claim 2, wherein said first and second roller means are of equal diameter.
 4. A roller-platen material-press as recited in claim 3, wherein one of said means for pressing has a relieved area at a position adapted to lessen pressure on the roller means proximate one end of the means for pressing.
 5. A roller-platen material-press as recited in claim 4, wherein the releasible wedging means includes a sideplate assembly, wherein the sideplate assembly rotatably mounts the first and second roller means and has clearance for pivoting about one of said rotatably mounted roller means and wedging the roller means between the means for pressing, wherein the sideplate assembly has an extended portion, wherein at least one guide is provided, and wherein said at least one guide is positioned for engaging the extended portion of the sideplate assembly and limiting pivoting in said wedging pivotal direction thereof.
 6. A roller-platen material-press as recited in claim 5, wherein said at least one guide limits only the side plate assembly extended portion pivoting during the pressure stroke, and wherein the rolling contacts of the roller means on passage between the means for pressing define the other motions of the roller means relative to the means for pressing during the working stroke.
 7. A roller-platen material-press as recited in claim 5, and laterally constraining means positioned for laterally aligning the roller means with respect to the means for pressing at a time when the sideplate assembly extended portion is pivoted away from engagement with said at least one guide.
 8. A roller-platen material-press as recited in claim 3, wherein the sideplate assembly includes first and second portions respectively mounting said first and second roller means, and a connector movably engaging the first portion of the sideplate means relative to the second portion of the sideplate means for thereby accomplishing said wedging of the roller means between the means for pressing.
 9. A roller-platen material-press as recited in claim 3, wherein the releasible wedging means and the means for reciprocating comprise first and second separately reciprocable means respectively mounting the first and second roller means.
 10. A roller-platen material-press as recited in claim 5, wherein said rotatable mounting by the sideplate assembly is substantially loose relative to the tightness of said wedging of the roller means between the means for pressing, thereby comprising said permitting means.
 11. A roller-platen material-press as recited in claim 1, and additionally a frame exteriorly proximate and substantially co-extensive with the width of a said means for pressing, and means for applying force selective between the means for pressing and the frame and thereby adjusting roller contact pressures with said means for pressing by altering the surface configuration of said means for pressing. 